It has become common on some automotive engines, to use a delay valve to control various functions. For example, a delay valve may be used as a spark delay valve in the control of exhaust emissions. The spark delay valve functions to delay the vacuum spark advance during light acceleration.
Among the objects of the invention are to provide a spark delay valve which will function to provide a desired prolonged time delay; which can be readily designed to provide different time delays; which can be readily manufactured and assembled; and which will provide an accurate predetermined time delay.